On 06/17/2011 09:59 AM, Benjamin Herrenschmidt wrote: > On Tue, 2011-06-07 at 21:59 +0530, Trinabh Gupta wrote: >> From: Len Brown<len.brown@xxxxxxxxx> >> >> useful for disabling cpuidle to fall back >> to architecture-default idle loop >> >> cpuidle drivers and governors will fail to register. >> on x86 they'll say so: >> >> intel_idle: intel_idle yielding to (null) >> ACPI: acpi_idle yielding to (null) >> >> Signed-off-by: Len Brown<len.brown@xxxxxxxxx> >> --- Hi Ben, Thanks for the review. > > When you carry over somebody's patch like this you need to also add your > own signed-off-by. Ok, thanks > > Have those generic changes been reviewed by whoever is in charge of that > cpuidle framework ? These patches were posted by Len Brown himself who is ACPI, Intel Idle cpuidle driver maintainer. He pulled in most of the patches that were part of that series (https://lkml.org/lkml/2011/4/2/8) in 3.0-rc1, but these few patches are still out there. These changes (removal of pm_idle) have already been agreed upon as they were initially reported by Peter Zijlstra himself (http://lkml.org/lkml/2009/8/28/43). Thanks -Trinabh > > Cheers, > Ben. > >> Documentation/kernel-parameters.txt | 3 +++ >> drivers/cpuidle/cpuidle.c | 10 ++++++++++ >> drivers/cpuidle/cpuidle.h | 1 + >> drivers/cpuidle/driver.c | 3 +++ >> drivers/cpuidle/governor.c | 3 +++ >> 5 files changed, 20 insertions(+), 0 deletions(-) >> >> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt >> index d9a203b..5697faf 100644 >> --- a/Documentation/kernel-parameters.txt >> +++ b/Documentation/kernel-parameters.txt >> @@ -546,6 +546,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. >> /proc/<pid>/coredump_filter. >> See also Documentation/filesystems/proc.txt. >> >> + cpuidle.off=1 [CPU_IDLE] >> + disable the cpuidle sub-system >> + >> cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver >> Format: >> <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] >> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c >> index 406be83..a171b9e 100644 >> --- a/drivers/cpuidle/cpuidle.c >> +++ b/drivers/cpuidle/cpuidle.c >> @@ -28,6 +28,12 @@ LIST_HEAD(cpuidle_detected_devices); >> static void (*pm_idle_old)(void); >> >> static int enabled_devices; >> +static int off __read_mostly; >> + >> +int cpuidle_disabled(void) >> +{ >> + return off; >> +} >> >> #if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT) >> static void cpuidle_kick_cpus(void) >> @@ -397,6 +403,9 @@ static int __init cpuidle_init(void) >> { >> int ret; >> >> + if (cpuidle_disabled()) >> + return -ENODEV; >> + >> pm_idle_old = pm_idle; >> >> ret = cpuidle_add_class_sysfs(&cpu_sysdev_class); >> @@ -408,4 +417,5 @@ static int __init cpuidle_init(void) >> return 0; >> } >> >> +module_param(off, int, 0444); >> core_initcall(cpuidle_init); >> diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h >> index 33e50d5..38c3fd8 100644 >> --- a/drivers/cpuidle/cpuidle.h >> +++ b/drivers/cpuidle/cpuidle.h >> @@ -13,6 +13,7 @@ extern struct list_head cpuidle_governors; >> extern struct list_head cpuidle_detected_devices; >> extern struct mutex cpuidle_lock; >> extern spinlock_t cpuidle_driver_lock; >> +extern int cpuidle_disabled(void); >> >> /* idle loop */ >> extern void cpuidle_install_idle_handler(void); >> diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c >> index 33e3189..284d7af 100644 >> --- a/drivers/cpuidle/driver.c >> +++ b/drivers/cpuidle/driver.c >> @@ -50,6 +50,9 @@ int cpuidle_register_driver(struct cpuidle_driver *drv) >> if (!drv) >> return -EINVAL; >> >> + if (cpuidle_disabled()) >> + return -ENODEV; >> + >> spin_lock(&cpuidle_driver_lock); >> if (cpuidle_curr_driver) { >> spin_unlock(&cpuidle_driver_lock); >> diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c >> index 724c164..ea2f8e7 100644 >> --- a/drivers/cpuidle/governor.c >> +++ b/drivers/cpuidle/governor.c >> @@ -81,6 +81,9 @@ int cpuidle_register_governor(struct cpuidle_governor *gov) >> if (!gov || !gov->select) >> return -EINVAL; >> >> + if (cpuidle_disabled()) >> + return -ENODEV; >> + >> mutex_lock(&cpuidle_lock); >> if (__cpuidle_find_governor(gov->name) == NULL) { >> ret = 0; >> >> _______________________________________________ >> Linuxppc-dev mailing list >> Linuxppc-dev@xxxxxxxxxxxxxxxx >> https://lists.ozlabs.org/listinfo/linuxppc-dev > > _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
